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Neutral and Cationic Palladium Complexes of P ‐Stereogenic Phosphanes Bearing a Heterocyclic Substituent
Author(s) -
Clavero Pau,
Grabulosa Arnald,
Rocamora Mercè,
Muller Guillermo,
FontBardia Mercè
Publication year - 2016
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201600608
Subject(s) - chemistry , stereocenter , cationic polymerization , allylic rearrangement , medicinal chemistry , substituent , palladium , amination , heteroatom , stereochemistry , crystal structure , tsuji–trost reaction , enantioselective synthesis , catalysis , ring (chemistry) , polymer chemistry , organic chemistry
The coordination chemistry of 13 optically pure P ‐stereogenic diarylmonophosphanes P(Het)PhR [Het = 4‐dibenzofuranyl (DBF), 4‐dibenzothiophenyl (DBT), 4‐dibenzothiophenyl S , S ‐dioxide (DBTO 2 ) and 1‐thianthrenyl (TA); R = OMe, Me, i Pr, Fc (ferrocenyl)] to Pd‐allyl moieties is described. Both neutral [PdCl(η 3 ‐(2‐methylallyl)(κ P ‐ P )] and cationic [Pd{η 3 ‐(2‐methylallyl)(κ P ‐ P ) 2 }]PF 6 complexes have been prepared. Coordination of the heteroatom of the heterocycle was only possible in the case of TA‐based phosphanes; these furnished complexes of the type [Pd{η 3 ‐(2‐methylallyl)(κ 2 P,S ‐ P )}]PF 6 after chloride abstraction with TlPF 6 . The crystal structure of the complex [Pd(η 3 ‐2‐methylallyl)(κ 2 P,S ‐PPh(OMe)(1‐TA)]PF 6 is reported. The neutral Pd complexes were found to be highly active in the hydrovinylation of styrene after activation with AgBF 4 , except for the TA‐based phosphanes. The cationic Pd complexes were evaluated in allylic alkylation and amination with the model substrate rac ‐ trans ‐1,3‐diphenylprop‐2‐enyl acetate ( rac ‐ I ), achieving total conversions and up to 70 % ee .